Thermodynamic properties of methylprednisolone aceponate.

In the present work, temperature dependence of heat capacity of methylprednisolone aceponate has been measured for the first time over the range from 7 K to 346 K by precision adiabatic vacuum calorimetry. Based on the experimental results, the thermodynamic functions of the methylprednisolone aceponate, namely, the heat capacity, enthalpy H °( T )− H °(0), entropy S °( T )− S °(0) and Gibbs function G °( T )− H °(0) have been determined for the range from T /K → 0–333. The enthalpy of combustion (−14304.4 ± 9.1) kJ·mol −1 of the methylprednisolone aceponate was determined for the first time using high-precision combustion calorimeter. The standard molar enthalpy of formation in the crystalline state (−1465.3 ± 9.8) kJ·mol −1 of compound at 298.15 K was derived from the combustion experiments. Using a combination of the adiabatic and combustion calorimetry results the thermodynamic functions of formation of the folic acid dihydrate at T = 298.15 K and p = 0.1 MPa have been calculated. [ABSTRACT FROM AUTHOR]